1This file contains some assistance for using "make *config".
2 3Use "make help" to list all of the possible configuration targets.
4 5The xconfig ('qconf') and menuconfig ('mconf') programs also
6have embedded help text. Be sure to check it for navigation,
7search, and other general help text.
8 9======================================================================
10General
11--------------------------------------------------
12 13New kernel releases often introduce new config symbols. Often more
14important, new kernel releases may rename config symbols. When
15this happens, using a previously working .config file and running
16"make oldconfig" won't necessarily produce a working new kernel
17for you, so you may find that you need to see what NEW kernel
18symbols have been introduced.
19 20To see a list of new config symbols when using "make oldconfig", use
21 22 cp user/some/old.config .config
23 yes "" | make oldconfig >conf.new
24 25and the config program will list as (NEW) any new symbols that have
26unknown values. Of course, the .config file is also updated with
27new (default) values, so you can use:
28 29 grep "(NEW)" conf.new
30 31to see the new config symbols or you can use diffconfig to see the
32differences between the previous and new .config files:
33 34 scripts/diffconfig .config.old .config | less
35 36______________________________________________________________________
37Environment variables for '*config'
38 39KCONFIG_CONFIG
40--------------------------------------------------
41This environment variable can be used to specify a default kernel config
42file name to override the default name of ".config".
43 44KCONFIG_OVERWRITECONFIG
45--------------------------------------------------
46If you set KCONFIG_OVERWRITECONFIG in the environment, Kconfig will not
47break symlinks when .config is a symlink to somewhere else.
48 49______________________________________________________________________
50Environment variables for '{allyes/allmod/allno/rand}config'
51 52KCONFIG_ALLCONFIG
53--------------------------------------------------
54(partially based on lkml email from/by Rob Landley, re: miniconfig)
55--------------------------------------------------
56The allyesconfig/allmodconfig/allnoconfig/randconfig variants can also
57use the environment variable KCONFIG_ALLCONFIG as a flag or a filename
58that contains config symbols that the user requires to be set to a
59specific value. If KCONFIG_ALLCONFIG is used without a filename where
60KCONFIG_ALLCONFIG == "" or KCONFIG_ALLCONFIG == "1", "make *config"
61checks for a file named "all{yes/mod/no/def/random}.config"
62(corresponding to the *config command that was used) for symbol values
63that are to be forced. If this file is not found, it checks for a
64file named "all.config" to contain forced values.
65 66This enables you to create "miniature" config (miniconfig) or custom
67config files containing just the config symbols that you are interested
68in. Then the kernel config system generates the full .config file,
69including symbols of your miniconfig file.
70 71This 'KCONFIG_ALLCONFIG' file is a config file which contains
72(usually a subset of all) preset config symbols. These variable
73settings are still subject to normal dependency checks.
74 75Examples:
76 KCONFIG_ALLCONFIG=custom-notebook.config make allnoconfig
77or
78 KCONFIG_ALLCONFIG=mini.config make allnoconfig
79or
80 make KCONFIG_ALLCONFIG=mini.config allnoconfig
81 82These examples will disable most options (allnoconfig) but enable or
83disable the options that are explicitly listed in the specified
84mini-config files.
85 86______________________________________________________________________
87Environment variables for 'silentoldconfig'
88 89KCONFIG_NOSILENTUPDATE
90--------------------------------------------------
91If this variable has a non-blank value, it prevents silent kernel
92config updates (requires explicit updates).
93 94KCONFIG_AUTOCONFIG
95--------------------------------------------------
96This environment variable can be set to specify the path & name of the
97"auto.conf" file. Its default value is "include/config/auto.conf".
98 99KCONFIG_TRISTATE
100--------------------------------------------------
101This environment variable can be set to specify the path & name of the
102"tristate.conf" file. Its default value is "include/config/tristate.conf".
103 104KCONFIG_AUTOHEADER
105--------------------------------------------------
106This environment variable can be set to specify the path & name of the
107"autoconf.h" (header) file.
108Its default value is "include/generated/autoconf.h".
109 110 111======================================================================
112menuconfig
113--------------------------------------------------
114 115SEARCHING for CONFIG symbols
116 117Searching in menuconfig:
118 119 The Search function searches for kernel configuration symbol
120 names, so you have to know something close to what you are
121 looking for.
122 123 Example:
124 /hotplug
125 This lists all config symbols that contain "hotplug",
126 e.g., HOTPLUG, HOTPLUG_CPU, MEMORY_HOTPLUG.
127 128 For search help, enter / followed TAB-TAB-TAB (to highlight
129 <Help>) and Enter. This will tell you that you can also use
130 regular expressions (regexes) in the search string, so if you
131 are not interested in MEMORY_HOTPLUG, you could try
132 133 /^hotplug
134 135______________________________________________________________________
136User interface options for 'menuconfig'
137 138MENUCONFIG_COLOR
139--------------------------------------------------
140It is possible to select different color themes using the variable
141MENUCONFIG_COLOR. To select a theme use:
142 143 make MENUCONFIG_COLOR=<theme> menuconfig
144 145Available themes are:
146 mono => selects colors suitable for monochrome displays
147 blackbg => selects a color scheme with black background
148 classic => theme with blue background. The classic look
149 bluetitle => a LCD friendly version of classic. (default)
150 151MENUCONFIG_MODE
152--------------------------------------------------
153This mode shows all sub-menus in one large tree.
154 155Example:
156 make MENUCONFIG_MODE=single_menu menuconfig
157 158 159======================================================================
160xconfig
161--------------------------------------------------
162 163Searching in xconfig:
164 165 The Search function searches for kernel configuration symbol
166 names, so you have to know something close to what you are
167 looking for.
168 169 Example:
170 Ctrl-F hotplug
171 or
172 Menu: File, Search, hotplug
173 174 lists all config symbol entries that contain "hotplug" in
175 the symbol name. In this Search dialog, you may change the
176 config setting for any of the entries that are not grayed out.
177 You can also enter a different search string without having
178 to return to the main menu.
179 180 181======================================================================
182gconfig
183--------------------------------------------------
184 185Searching in gconfig:
186 187 None (gconfig isn't maintained as well as xconfig or menuconfig);
188 however, gconfig does have a few more viewing choices than
189 xconfig does.
190 191###
192